1. Field of the Invention
The present invention is broadly concerned with a low head pressure, non-clogging water distribution nozzle assembly especially designed for use in counterflow water cooling towers, including those of the mechanical draft as well as so-called natural draft towers. More particularly, it is concerned with such an assembly having, in preferred forms, a hollow-cone, swirl-type nozzle, along with a series of circularly arranged water-dispersing buttons disposed below the nozzle outlet and in circumferentially spaced relationship to one another for deflecting and dispersing water from the nozzle and in effect converting the hollow cone nozzle into a full cone spray nozzle.
2. Description of the Prior Art
Electrical utilities and other types of large scale industrial plants generally employ water cooling towers of one type or another for handling the large quantities of hot water produced during plant operations. In the case of utilities, very large towers of the natural draft counterflow variety are often employed. In such towers quantities of initially hot water are sprayed downwardly through the use of nozzles or the like over fill structure, while air currents are drawn upwardly in direct opposition to the descending water for cooling purposes. As can be readily appreciated, in order to be most efficient, such a counterflow tower must be equipped with nozzles or like mechanisms which effectively disperse the water to facilitate cooling thereof. At the same time, resistance to airflow on the part of the water-dispersing equipment must be minimized, in order to permit adequate quantities of air to be drawn in opposition to the descending hot water.
In the operation of a plant water cooling system, it is a common practice to periodically place a number of foamed plastic or cellular synthetic rubber-like balls into the cooling water in order to clean and clear out plant heat exchange tubes forming a part of the overall water cooling system. The balls are sized to be slightly larger in diameter than the pipes through which they are passed for cleaning purposes and therefore are generally available in diameters ranging from about 1/2 in. up to about 11/2 in. Exemplary cleaning balls are sold under the trademark Amertap by Amertap Corporation. Given this practice, it will be seen that the associated cooling tower, and particularly the water-dispersing nozzles thereof, must be so constructed as to accommodate flow of such balls therethrough. Furthermore, even though such cleaning balls are normally removed after each use thereof, it inevitably follows that a number of the balls escape from the collection device and remain in the system to be continuously circulated through the tubes, cooling tower, and other portions of the overall cooling system; thus, the nozzles of the cooling tower must be capable of safely clearing such balls at all times.
Since water cooling systems are open to the atmosphere, it necessarily follows that the cooling water becomes contaminated to a certain extent with extraneous foreign objects such as fibers, twigs, scale and other particulate materials. The water dispersion and distribution systems must also clear these materials.
U.S. Pat. No. 3,617,036 describes a cooling tower nozzle particularly adapted for use in crossflowtype towers, but this nozzle is substantially different in structure and intended operation than the nozzle assembly of the present invention.